Hold-up alarm transmitting means



July 10, 1934. J. H. DERBY HOLD-UP ALARM TRANSMITTING MEANS Filed May 15, 1931 2 Sheets-Shet, l

I (xx, 1111 r rgNTO' R BYms ATTORNEYS M4 July 10, 1934. J H, DERBY 1,966,062

HOLD-UP ALARM TRANSMITTING MEANS Filed May 15, 1931 2 Sheets-Sheet 2 7 INVENTQR 74' fafifl Derby BY ms ATTORNEYS 76 I M Patented July 10, 1934 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to means for closing an alarm circuit and is particularly intended for sending alarms in cases of hold-up or attempted robbery of banks and other places where fire- 5 arms are usually employed to intimidate the tellers, cashiers or other employees or ofiicials of the institution in which the hold-up or attempted robbery occurs.

7 Robberies of the hold-up type are affairs which 10 are carried out in a very short space of time and in which both the robbers or highwaymen and the employees of the institution being robbed are under very severe nervous tension, the robbers par- I ticularly being intent upon seeing that no alarm is given or other attempt made to frustrate their plans. It is therefore important that any provision for transmitting an alarm in cases of holdup be so arranged and the transmitting means so constructed and operated as not to attract the attention of the robber when the alarm signal is sent.

Various devices, usually operated by the foot or the leg of the teller, cashier or other employee who is liable to be covered by a gun in the case of a hold-up, have been devised and employed, but difficulties have been encountered in their use. In order to prevent accidental alarms it has been necessary so to place the part to be operated to send the alarm that it is not liable to be operated accidentally. Such location of the part to be engaged to sound the alarm has usually resulted in the necessity for an awkward movement on the part of the person being held up in order to engage and operate the alarm-sounding mechanism. This at once calls the attention of the robber to the attempt of his victim to sound an alarm and has frequently resulted in the shooting of the one attempting to sound the alarm.

In addition to this, the alarm-sending mech- 4 anism has been so constructed that even when the alarm itself is out of hearing of the people where the robbery is taking place an audible sound must be made to send the alarm. This has been particularly true of that type of circuit-closing mechanism in which the circuit closer, when actuated, remains or is locked in circuit-closing position until it is released by a distinct operation such, for example, as unlocking it with a key.

An object of the present invention is to provide an improved hold-up alarm transmitting device which can be operated under substantially any circumstances attendant upon a hold-up without in any way attracting the attention of the bandit or robber and thus without endangering the life of the one being held up.

Another object of the invention is to provide an alarm signal-transmitting device which is so constructed and so operated that it is not liable to accidental operation and yet can be actuated to transmit a signal and to continue to transmit 00 a signal with a minimum of effort and without any audible sound.

A further object of the invention is to provide an alarm signal-transmitting device in which the parts are so constructed and of such materials that with a minimum of attention the device will remain in condition to operate with certainty whenever the need for its operation arises. The invention also contemplates the provision of means for automatically supervising all parts of the signal circuit and as much of the signaltransmitting means as it is necessary to retain in operative condition to insure sending the signal.

Other objects and important features of the invention will be pointed out in or appear from the following description and claims when considered in connection with the accompanying drawings in which Figure 1 is a vertical section through an alarm signal-transmitting device embodying the present invention;

Figure 2 is a plan view of the device with the cover removed;

Figure 3 is a transverse section on the line 3--3 of Figure 1;

Figure 4 is a detail front elevation of the lock for locking the cover in position;

Figure 5 is a full size partial vertical section on the line 5-5 of Figure 1 with the parts in open circuit position.

Figure 6 is a section similar to Figure 5 with the parts in circuitclosing position, and

Figure 7 is a wiring diagram showing the arrangement of a combined supervising and signaltransmitting circuit including a plurality of signal-transmitting devices in parallel.

The alarm signal-transmitting device, in whichthe invention, for illustrative purposes, is shown as embodied, is of the type particularly designed for banks, cashiers cages and similar places where the one who receives or pays out the money usual- 1y stands or sits at a raised shelf or desk and is provided with a foot rest on which one or both feet may be placed according as the employee is standing or sitting, and in the illustrative preferred embodiment of the invention, circuit closing mechanism is associated with and is preferably partly enclosed within a foot rest especially designed for carrying the signal-transmitting means.

In the illustrative embodiment of the invention, the housing 2, within which the circuit-closing means and the means for yieldingly holding it in its open condition and positively holding it in its closed position are located and which is supported above the floor by legs 4 formed by downward extensions of the side walls of the housing, is provided with a cover 6 so inclined as to form a convenient foot rest, the cover 6 being hinged at 8 to the housing so that it may be swung into open or closed position and having a flange 10 at its front edge which overlaps the front of the housing and on which is pivoted a closure 12 for an opening 13 in said flange through which the key for operating the cover lock 14 may be inserted. The lock 14, as illustrated, comprises a screw extending, when in looking condition, into a registering opening 15 in the housing 2 and being carried by an angle piece 16 welded or riveted to the inside of the cover 6. The screw 14 is provided with key-engaging lugs 18 by which it may be turned into or out of locking position in the hole 15 in the housing 2.

The housing 2 and its associated cover 6 are preferably elongated to furnish a foot rest of considerable longitudinal extent, for example 16 to 18 inches or more, and there is preferably associated with the housing means for operating the circuit-closing mechanism which is approximately of the longitudinal extent of the foot rest itself, and is preferably at least of such extent that it may be engaged and operated by the foot placed anywhere beneath the foot rest.

Ihe illustrative alarm signal-transmitting means, embodying the present invention, comprises a mercury switch or circuit closer 20 of the type in which mercury is confined within an elongated enclosed tube or bulb through one end of which extend the terminals 22 and 24 of a normally open circuit, or preferably of a resistance short-circuiting bridge in a normally closed cir cuit supervised by a current below signal operating level but sufficient to hold any suitable trouble alarm inoperative, the mercury switch 20 being so mounted that it may be tilted from a position like that shown in Figure 5 in which the mercury is caused to flow to the end of the bulb away from the terminals 22 and 24, and thus out of circuitclosing relation thereto, to a position like that v shown in Figure 6 in which the bulb is inclined in the other direction, thereby causing the mercury to come into bridging or circuit-closing relation to the terminals 22 and 24.

There are many advantages in using this type j, of switch in the present invention. In the first place, its circuit-closing movement can be made completely inaudible at a very short distance therefrom and, in the second place, the terminals are so enclosed and free from oxidizing agents U that regardless of the length of time between operations of the switch it is always in condition to operate with certainty.

To effect the convenient tilting of the mercury switch 20 between its open circuit and its circuit-closing positions, it is preferably mounted upon one arm of a lever, which may conveniently be of the bellorank type, so that as the lever is rocked about its fulcrum the mercury switch will be tilted to cause its contained mercury to flow either into ci cuit-closing position or into circuitbreaking position. In the illustrative embodiment of the invention, two bellcranks are shown near opposite ends of the housing, these bellcranks being preferably pivoted at 26 between ears 28 formed by depending angles either welded or riveted to the under side of the housing 2. One arm 30 of each bellcrank is shown as extending up through a slot 32 in the bottom of the housing 2, this slot 32 being of sufiicient length to allow the bellcrank to swing between its extreme positions, without contact with the housing, and the other arm 34 of each bellcrank extends more or less horizontally forwardly from the pivot or fulcrum 26 of the bellcrank and is connected to one end of a horizontal bar 36 adapted to be engaged by the upper side of the foot of the one who is to operate the alarm signal-transmitting means.

To keep dust and other foreign matter from entering the housing 2 through the slots 32 and at the same time to help to deaden any sound incident to the movement of the bellcranks on their fulcrums 26 between the ears 28, a piece of felt 38 of substantial thickness, closely fitting the arm 30 on the bellcrank and covering the slot 32 in all positions of tins arm is provided a pin 40 extending through the arm 80 and bearing against the upper side of the felt 38 tending to hold it constantly in dust-sealing relation to the slot 32. To insure rigidity of the parts and constant register of the bellcranks with their slots and at the same time to provide convenient means for holding the alarm signal-transmitting means in its respective positions and for deadening the sound of the switch-closing movement thereof, the bellcrank arms 30 within the housing 2 are also preferably connected with a horizontal rod or bar 42, the two bellcranks with the two rods or bars 36 and 42 thus forming a rigid rectangular structure that is not liable to become distorted or to have its parts moved out of proper relation to the parts by which they are pivotally carried and with respect to which they move. This rigid, accurately alined construction, therefore, insures against any accidental rubbing of the parts which might cause a sound at the critical time when the mechanism is to be operated to send in a hold-up alarm.

As shown particularly in Figs. 5 and 6 of the drawings, at least one, and preferably both of the arms 30 of the bellcrank is provided with a stopcarrying arm 44 carrying an adjustable stop 46 in the form of a screw threaded through the arm 44 and provided with lock nut 48 by which it is locked in adjusted position. The purpose of this stop, as shown in Figs. 3 and 5 of the drawings, is to determine the open circuit position of the parts and particularly the depressed position of the rod 36 which is to be engaged by the foot.

It will be obvious that only one mercury switch 20 is absolutely necessary for each complete combined signal transmitting device and foot rest and that this may be mounted on either of the bellcrank arms 30 or even at some intermediate point between them so long as it is so connected thereto as to partake of the rocking movements of the bellcranks. Preferably as shown an adjustable holder for a mercury switch 20 is provided on each of the bellcranks 30 to accommodate the varying wiring conditions, and also to permit the use of two mercury switches in parallel where it is desired to insure against accidental breakage of one, this holder comprising a spring clip 50 shaped to embrace and hold the mercury switch 20, this clip being preferably mounted upon a spring member 52 carried upon a horizontally i clip 50,with respect to the bellcrank arm 30 to adjust the inclination of the mercury switch 20 to the varying adjustments of the stop 46.

It is desirable when the alarm circuit is closed to send an alarm signal that it remain closed and continue to transmit the alarm without further manipulation, and it is important therefore that means be provided for preventing readily opening the circuit after it has once been closed so that the bandit or robber cannot stop the alarm from continuing after one of his victims has succeeded in operating the alarm-transmitting mechanism. To this end means is preferably provided within the locked housing for positively holding the mechanism in its circuitclosing position when it has once been moved to this position until the housing is opened by means of a key fitting the lock and the parts manually restored to their open circuit position.

In the illustrative embodiment of the invention, a spring member 56, welded or riveted to the inside of the housing, is provided with a depressed portion 58 that embraces the rod 42 when the mechanism has been moved into the position shown in Fig. 6 of the drawings, the depressed portion of the spring fitting sufficiently around the rod so that the parts cannot be moved again to open circuit position by merely pressing down on the foot-engaging rod 36. The spring 56 at its forward end has a lip 60 which bears against the under side of the rod 42 when the parts are in open circuit position and thus holds the spring tensioned ready to move its locking position into locking engagement with the rod 42 when the bellcrank is rocked to transmit an alarm. Another spring 62 connected at one end to an eyelet 64 carried by the rod 42 and at its other end to a stud 66 on the inside of the front of the housing tends to hold the parts in open circuit position. It requires, however, a comparatively slight pressure upward on the rod 36 to move it to a position where the rocking of the bellcrank will bring the rod 42 within the embrace of the depression 58 of the spring 56.

To insure noiseless operation in the circuitclosing movement of the parts, the rod 42 where it engages the spring 56 is surrounded by suitable sound-deadening means 86, such, for example, as felt, and the rod 36 is also provided at its ends, where it may engage the under side of the housing 2, with similar sound-deadening cushions of felt or other suitable material '70. thus insuring that the entire operation of the device will be noiseless or at least so nearly noiseless that the sound of the circuit-closing movement can be heard at most only a very few inches from the device.

In order to insure proper supervision of the circuit in which the alarm-transmitting mechanism of the present invention is to be situated, I prefer to arrange the switch 20 so that it constitutes a short circuiting bridge for short circuiting the supervising resistance in a normally closed circuit through which constantly flows a current maintained below alarm-operating level by means-of the resistance which is to be short circuited. This resistance may conveniently be made a part of the structure provided and, in the illustrative embodiment of the invention, resistance in the form of a resistance coil 72 is shown as located within the housing 2. This resistance may be at the end of an alarm circuit going to a central supervisory panel on which is the usual trouble indicator, not shown or de scribed. The wiring of an individual circuit to an alarm transmitter is illustrated in Fig. 7 of the drawings. In this figure each bellcrank arm is shown as provided with a mercury switch 20, these switches, as shown, being in parallel across a circuit leading from the positive terminal 74 to the negative terminal 76 through the resistance '72, the closing of either switch 20 serving to short circuit the resistance 72 out of the alarm circuit thus permitting the flow of current through the circuit to increase sufficiently to transmit the alarm signal. In this manner supervision of the circuit is provided practically to the mercury tube switch itself, any break in the circuit upon to the switch itself serving to interrupt the constant flow of supervisory current through the circuit and to operate any suitable trouble alarm in accordance with the well known manner of providing supervision of circuits of this type.

Although the alarm-transmitting device is preferably employed in a circuit that is automatically supervised, for example, in the manner just described, it may, of course, serve to close an alarm circuit that is normally open or interrupted so that no current flows through it except when the alarm-transmitting mechanism is actuated. It will be understood, therefore, that the references in the specification and claims to circuit closing, closed circuit etc. are intended to embrace both the closing of an interrupted circuit to the alarm device and the short-circuiting by the transmitting mechanism of resistance which maintains the current flow in a normally closed circuit below operating level.

From the foregoing description it will be seen that the present invention provides alarm-transmitting means for transmitting an alarm signal in case of hold-ups, which is so constructed, arranged and supervised that it will always be ready for the emergency and which is so simply, easily and noiselessly operated that it is practically always possible to operate it without attracting attention when the emergency does arise.

What is claimed as new is:

l. A silent switch comprising a housing, a rocker mechanism mounted in said housing having an arm extending therethrough for manual operation from outside said housing and adapted to be moved from open circuit to circuit closing positions without striking any rigid part, switch means associated with said rocker mechanism within said housing adapted to be closed by said mechanism when in one position and to be open when said mechanism is in another position, a spring detent adapted to hold the rocker mechanism in one of said positions, and a sound deadening cushion between the detent and the rocker mechanism whereby, upon movement of the latter, the springing of the detent and its impact when sprung to locking position will be silenced.

2. A normally open locked switch comprising a normally closed housing, a rocker mechanism mounted in said housing and having an arm extending therethrough for manual operation of said switch from outside said housing, a switch within said housing associated with said rocker mechanism and operated thereby, a detent within said housing adapted to hold the switch when moved to an operated position, and locking means on said housing requiring a substantial delay for the opening of said housing whereby the switch when operated from outside said housing must be left in the operated position for a substantial time before the detent can be released.

JOHN H. DERBY. 

